基于电-力导纳型类比法电厂动力设备被动隔振机理分析

为分析单自由度弹簧被动隔振技术的隔振机理,采用电-力导纳型类比法求得阻尼系统振动方程。利用归一化处理方法考察了在不同频率比(z)和力学品质因子(Q_m)影响下,设备位移、速度、加速度的响应情况。分析发现,在z<1时,设备响应特性关系为位移>速度>加速度;在z>1时,设备响应特性关系为位移<速度<加速度;而当z=1时,设备响应特性关系为位移=速度=加速度,此时系统发生共振,且力学品质因素越大系统振动越剧烈;而当基础的干扰频率为系统固有频率的2 倍时,设备振动特性不受Q_m影响,且位移、速度和加速度传递比分别为1,2 ,2。该分析结果可为动力设备布置竖向弹簧隔振支座的隔振设计提供参考。

Mechanism analysis of passive vibration isolation of power equipment in power plant based on electro-force admittance analogy

To analyze the vibration isolation mechanism of single-degree-of-freedom spring passive vibration isolation technology, the vibration equation of damping system is obtained by electric-force admittance analogy method. The normalization method is used to investigate the response of equipment displacement, velocity and acceleration under the influence of different frequency ratio z and mechanical quality factor Q_m. It is found that when the frequency ratio is less than 1, the equipment response characteristic relation is: displacement > velocity > acceleration; when the frequency ratio is greater than 1, the equipment response characteristic relation is: displacement < velocity < acceleration; whenthe frequency ratio is equal to 1 , the equipment response characteristic relationship is : displacement =velocity = acceleration, when the system resonates, and the greater the mechanical quality factor, themore intense the vibration of the system. When the interference frequency of the foundation is twicethe root sign of the natural frequency of the system, the vibration characteristics of the equipment arenot affected, and the transfer ratios of displacement, velocity and acceleration are 1 , and 2,respectively. The analysis results can provide a reference for the vibration isolation design of verticalspring vibration isolation bearings for power equipment.